Compressor.



FA. RIDER.

COMPRESSOR. APPLIOATION FILED AUG. 2a. 190s.

Patented May 18, 1909.

8 SHEETS-SHEETV 1.

I'. A. RIDER.

COMPRESSOR.

APPLICATION FILED Amma 19o Patented May 18,1909.

3 SHEETS-SHEET 2.

P. A. RIDER.'

COMPRESSOR.

APPLIUATION FILED AUG. za, 190s.

Patented May 18, 1909.

IIL/ll,

3 SHEETS-SHEET 3.

NSTSLS NVENTOR UNTE STAT FRANK A. RIDER, OF PITTSBURG, PENNSYLVANIA.

COMPRESSOR.

To all whom it may concern.'

Be it known that I, FRANK A. RIDER, of Pittsburg, in the county ofAllegheny and State of Pennsylvania, have invented certain newand usefulImprovements in Compressors and 1 do hereby declare the following to bea full, clear, and eXact description of the invention, such as willenable others skilled in the art to which it appertains to make and usethe same.

My invention relates to improvements in compressors, and moreparticularly to improved valved pistons for ammonia compressors,theobject of the invention being to provide simple and eflicient means foreffecting the operation of the valves in the pistons of ammoniacompressors, Without the use of springs and so that the valve will beclosed quickly after the piston has finished its retreating stroke andjust before it begins the compression stroke.

A further object is to provide means for effecting the alternate openingand closing of valves carried by two pistons of a compressor and to soconstruct such means that the valves of both pistons will be closed fora limited time at the end of each stroke.

A further object is to provide means operative by the weight and inertiaof an independently-movable part, for controlling the operation of avalve in the piston of a compressor.

With these objects in view the invention consists in certain novelfeatures of construction and combinations of parts as hereinafterdescribed and pointed out in the claims.

ln the acconipanyin@5 drawings, Figure 1 is a longitudinal sectionalview of a compressor embodying my improvements; Fig. 2 is a transversesectional view, and Figs. 3, 4L and 5 are longitudinal sectional viewsillustrating certain modifications; Fig. 3a is a transverse sectionalview of the structure shown in Fig. 3.

1 represents a cylinder of a compressor provided at an intermediatepoint with an inlet 2 and at its respective ends with outlets 3, inwhich latter check-valves 4L may be located. Two pistons 5, 5, arelocated within the cylinder at respective sides of the center thereofand each of said pistons is provided centrally with a hub 6 connectedwith the main or body portion of the piston Specification of LettersPatent.

Application led. August 28, 1908.

Patented May 18, 1909.

Serial No. l150,719.

by means of webs 7. rlhe forward end of each piston is open and providedwith a seat 8 for a valve 9. Each valve 9 is provided with an inwardlyprojecting annular iange or collar 10 which surrounds the forwardportion of the piston hub and from each flange or collar 10 a series ofarms or rods 11 project through the spaces between the webs 7 andterminate a comparatively short distance beyond inner ends of thepistons, in shoul ders 12. A piston rod 13 (to which power is appliedfrom any convenient source) passes through the two pistons and issecured in any suitable manner to the hubs of the latter and this pistonrod also passes loosely through the valves 9. Mounted upon the pistonrod 13 intermediate of the two pistons and adapted to be movableindependently of both is a member 14 which, for convenience, may betermed an inertia piece. The member 14 has a sliding iit on the pistonrod 13 and is provided at its respective ends with heads 15 provided attheir edges with inwardly projecting 'lianges which afford cylinders 16to cooperate with the shoulders 12 on the valve rods 11. rllhe spacebetween the outer ends of the piston hubs and the rear faces of thevalves, will constitute gas cushions 17. With the construction hereindescribed, the valves of both pistons will be closed for a limited timeat the end of each stroke which, in the practical operation of thecompressor, is advantageous.

/Vhen the pistons start from one end of their stroke to travel to theopposite end thereof, a partial vacuum will be formed behind the rearpiston and the effect of this will be to cause the valve of said rearpiston to open. The valve of the forward iston must of course be closed,and this willpbe permitted by the pressure in front of said'forwardpiston. During the movement of the pistons from one end of the stroke tothe other, the shoulders 12 of the rods 11 of both valves will be inengagement with the shoulders 16 of the inertia piece or member 15. Whenthe pistons reach the end of the stroke the inertia piece will continueto move forwardly a short distance and eifect the closing of the valveof the rear piston, but will not open the valve of the forward pistonbecause the forward shoulder 16 of the inertia piece will move away fromthe shoulder 12 of the rods of the forward piston valve. By such leo ,and permit the iiuid to flow from the inlet v2' through the rear pistonto the space behind the latterfready to be forced through an outlet-3atone end ofthe cylinder when the piston4A beginsy to move in thereverse direction. lt will -be observed lthat after thepistonhascompleted its stroke and delivered its charge olf-compressed gas, itstartsl to returnlon a suction stroke. If the Valveopened immediately itVwould have the effect of closingthe opposite valvequickly," which isthe desired effect, but owing -to some gas being-compressed in theclearance space the retreating piston cannot open its valve until thepressure of this gas in theclearance has expended itself. While sodoing, ofl course, both valves would be closed, but this is only forasmall fraction of time and is represented on the indicator card byl arounded corner.

The object of the inertia piece is to causo the valve to close quicklyat the end of the suction stroke. lf 1t does not do so, it will bedrawnshut by the action of the other valve opening, due to a vacuum behindthe latter. lt will lbe seen that two means-are provided for forcing thevalve to close at the end of the suction stroke, one being the inertiapiece and-this being assisted by the opening of the other valve when ithas started back and reduces a partial vacuum. lf desired, pac ing rings18 may be located lin suitable grooves in the hubs of the pistons wherethe collars 10 of the valves move on said hubs.

The operation of the construction shown in Fig. 3 is the same as thatabove described. In Fig. 3 l have shown two inertia pieces 22-22 mounted`on the pistonrod so as to form a lost-motionspace 23 between them equalto the opening of one valve.` Each inertia piece is provided with athreaded portion 24 with which the valve rods 25 are connected. I

ln the construction shown in Fig. d," the lost motion devices abovedescribedl are omitted and the valves of the respective pistons areconnected together by means lof valve rods 19, so that when one of thevalves is opened by the action of the partial vacuum behind -it in thecylinder l, the other valve will beclosed,the closing of the last-mentioned vvalve and the opening ofthe other valve being assistedbyfpartial vacuum-behind. the retreating piston:

ln the construction shownv inn Fig. 5, the valve of eachpiston isconnected through the medium of its rod 20 with an inertia piece ormember. 2l gmountedlwithinithe cylinder an d havingfrictional contactwith the wall'of the latteE,-sad- .inerti aapiece or member being spacedfrom the mainbody of the piston whenw the valve is closed. With thisconstruction the inertia of the member 2l and its ,frictional contactwith the wallioftheylinder will effect the opening and 'closing of thepiston valves Vat the-ends of their strokes,-

VVtle valve in one piston being opened and the valve in theother'piston1-closedf;

Other slight changes. might beimadeginithe details of construction ofmyinventi'orrivvlitll out?V departing from thespiritrthereofgordmb itingits Vscope and hence.r l ;doi.not.vwislr tofre1 strrt f myself 7to.theprecise details. herenlrset fort Having fullydescribedinyfmventiolrwhat I vclaim as newanddesire to secure by LetteIS Patent,is

l. The :combination with .=a...`cylinder, ,two pistons therein, and Aapiston/rod secure/dito said pistons, of a valve for each; pistoinandmeans for operating said. valvesftocloseione and `open the otherfor.eaehstroke-offsaid pistons, andl means to permitabothztoabe closedsimultaneously.

2. The combination with-L. a cylindenma piston therein, amd-arod'securedwtopsaid piston, of a valve nfor. Vcontrolling.the-,apassageof fluid through saidpiston, andsfan-.inertia membermovablewithethefvalve and having lost-motion relation tothepistomfwherebyit will move the valve when t 'e pistonstopsf.

3. The combination: with.. a cylinder,v two pistons therein, and fapistoni-rod secured'frto and connecting said pistons, ofiayalvetfor eachpiston, and lost motion-conneotionsfbetweenthevalves of thefr'espective:pistons y:

4. The. combination`r with a cylinder,- two pistons therein, and aistonrod secured-to and connecting said pistons, of avalveffor each piston,an inertia .membermounted on the piston rod betweenl the-pistons,andfilost motion connections between said# inertia member and vthevalves offI theerespective pistons.

' 5.' The combination withiacylinder, of a piston therein, having ahubfa rodseeuredsto said hub, a val-vefor opening andiclosingcommunication through:v said f piston, said valve having -an-annuarflange-embracing and movable on the hubfof Ithe fpistonf, valve rodsprojecting from saidilangeandfpassing through the piston, and meansff-coperatmg between the pistons andf` provi-decis with shoulders tocoperate with the shoulders of piston, and connections the valve rods,the shoulders of the valve rods and the shoulders of the inertia memberbeing so disposed as to permit 10st motion bei tween them.

7. The combination with a cylinder7 two pistons therein, and means formoving said pistons simultaneously, of a Valve in each between theValves of the two pistons and tending to close one of said Valves whenthe other opens, and ineens to permit both to be closed simultaneously.

In testimony whereof, I have signed this speeiiieation in the presenceof two subscribing witnesses.

FRANK A. RIDER.

Witnesses B. B. WHITING, A. E. THOMAS.

